A comprehensive study of (CH3)2CHOC(S)SC(O)OCH3 using matrix isolation technique, spectroscopic studies and theoretical calculations

TOBÓN, YENY A.; ROMANO, ROSANA M.; HEY-HAWKINS, EVAMARIE; BOESE, ROLAND; DELLA VEDOVA, CARLOS O.

JOURNAL OF PHYSICAL ORGANIC CHEMISTRY

JOHN WILEY & SONS LTD

Año: 2009

0894-3230

Abstract. Potassium isopropyl xanthate, (CH3)2CHOC(S)SK, reacts with methyl chloroformiate ClC(O)OCH3 to yield (Methoxycarbonyl) (2-propoxythiocarbonyl) sulfide, (CH3)2CHOC(S)SC(O)OCH3. This novel xanthogen formate has been purified and characterized by 1H and 13C NMR, mass spectrometry and IR and Raman spectroscopy. Its conformational properties have been studied by liquid IR and Raman spectroscopy, matrix isolation spectroscopy together with photochemical studies and quantum chemical calculations [HF, and B3LYP methods with the 6-31+G* bases set]. The analysis of the IR spectrum of liquid (CH3)2CHOC(S)SC(O)OCH3 suggests the presence of two conformers in equilibrium at room temperature. However, in the photochemical matrix study, an equilibrium of three conformers was detected. These forms were further characterized by theoretical calculations. Different photolysis products, such as CH3OC(O)SCH(CH3)2, OCS, CO, CO2 and CS2, were identified by matrix spectroscopy. The IR absorptions of CH3OC(O)SCH(CH3)2, for which literature data are scarce, were analyzed in the light of the results of appropriate theoretical calculations. The structure of a single crystal was determined by X-ray diffraction analysis at 173 K.